1. Field of the Invention
The present invention generally relates to a recording apparatus for recording a video signal and more particularly is directed to a recording apparatus for recording a video signal obtained from a high speed scanning video camera which can pick up and record a phenomenon moving at high speed by using a television camera and a VTR (video tape recorder).
2. Description of the Prior Art
In the prior art, a high speed film camera is proposed as an apparatus for picking up and recording a phenomenon moving at high speed. This high speed film camera, however, has a defect that the phenomenon moving at high speed, which is recorded by such camera, can not be reproduced immediately. To remove the above defect, various researches and technical developments have been made in which a phenomenon moving at high speed is picked up by a television camera, recorded by a VTR or the like, and then reproduced immediately.
As is known well, it takes 1/60 second at minimum for an ordinary television camera to convert one sheet of picture to an electrical signal. Accordingly, it is impossible for the television camera to pick up a moving object which changes at a speed faster than 1/60 second. To solve this problem, a technique is disclosed in, for example, the publication document of the Japanese patent application examined, No. 26416/1977, in which the visual field of a pickup tube is divided into a plurality of sections, the whole of an object is placed in each one section of the divided sections and the object image on the pickup tube is scanned during the scanning period of time corresponding to each section to thereby enable the phenomenon moving at high speed to be picked up.
Further, in the published document of the Japanese patent application examined, No. 13631/1980, there is disclosed a technique in which the optical image of an object is sequentially projected onto a plurality of pickup tubes having accumulation effect at every constant interval during a constant time period, and the video signals from the respective pickup tubes are respectively supplied to a plurality of recording apparatus to thereby successively record the time image of the phenomemon moving at high speed.
In addition, in the publication document of the Japanese patent application unexamined, No. 2119/1977, there is disclosed a technique in which two image pickup elements or imagers are employed and the deflections thereof are mutually displaced by every 1/2 frame to thereby produce a video signal of high speed twice the frame speed.
However, according to the technique disclosed in the published document of the Japanese patent application examined, No. 26416/1977, since the visual field is substantialy narrowed, only the image of the periphery of the moving object is obtained. Also since the movable range of the moving object is confined within the divided one section, this technique is not suitable for the general use. According to the technique disclosed in the published document of the Japanese patent application examined, No. 13631/1980, since a plurality of image elements having accumulation effect and a plurality of recording apparatus are required, the arrangement thereof becomes complicated, which then becomes significantly inconvenient in practical use. Furthermore, according to the technique disclosed in the publication document of the Japanese patent application unexamined, No. 2119/1977, since this technique requires a plurality of image pickup elements and the recorded pattern on a magnetic tape becomes special, the recorded tape has no compatibility.
In addition, it may be considered that a video signal picked up by the television camera at a scanning speed a plurality of times (N) higher than the ordinary scanning speed is recorded as it is by using the VTR. In that case, it is necessary to set the revolution number of the rotation drum of the tape guide drum at N times the standard value and to set the tape transport speed at N times the standard value. This, however, will cause the following problems.
(1) In order to cause the tape guide drum to rotate at a revolution number N times the standard revolution number, it is necessary to set the carrier frequency of FM-modulation (frequency-modulation) and the base band frequency both N times higher than the standard values. However, in this case, although the signal recorded at the speed N times the standard value must be reproduced at the normal speed, it is quite difficult to secure the corresponding relation between the emphasis and deemphasis and the characteristics of the recording and reproducing circuits with the frequency stability or the like of the frequency-modulated signal frequency. In addition, the recorded tape has no compat- ibility.
(2) Since the frequency-modulated carrier frequency becomes N times the normal value, considering the impedance of the rotation magnetic head, the characteristic of the rotary transformed and so on, it is quite difficult to increase the value N.
(3) If the revolution number of the rotation drum of the tape guide drum is set to N times the normal value, there is some fear that the contact pressure of the rotation magnetic head for the magnetic tape is lowered by a so-called air film to lower the recording sensitivity. OBJECTS AND SUMMARY OF THE INVENTION
Accordingly, it is an object of the present invention to provide an improved recording apparatus for recording a video signal obtained from a high speed scanning video camera.
It is another object of the present invention to provide a recording apparatus for recording a video signal obtained from a high speed scanning video camera which can easily pick up and record a phenomenon moving at high speed by using a television camera and a VTR (video tape recorder).
It is a further object of the present invention to provide a recording apparatus for recording a video signal obtained from a high speed scanning video camera which is compatible with the VTR of a standard type or C-format of the SMPTE (society of motion picture and television engineers).
According to one aspect of the present invention, there is provided a recording apparatus for recording a video signal obtained from a high speed scanning video camera which comprises a memory means for storing therein a video signal derived from a high speed scanning video camera the scanning speed of which is faster than the scanning speed of the standard television signal and a plurality of rotation magnetic heads supplied with the video signals of a plurality of channels read out in parallel from the memory means wherein the video signals of the plurality of channels are recorded on the magnetic tape by the plurality of rotation magnetic heads so as to form adjoining slant tracks sequentially
According to the present invention, it is possible to obtain a recording apparatus for recording a video signal obtained from a high speed scanning video camera which can easily pick up and record the phenomenon moving at high speed by using a television camera and a VTR and the recorded tape of which can be reproduced by a conventional VTR of SMPTE standard type (C format).
The other objects, features and advantages of the present invention will become apparent from the following description taken in conjunction with the accompanying drawings through which the like references designate the same elements and parts.